文献类型：期刊文献

中文题名：PVDF成膜过程中溶剂分布的模型计算及其大孔形成机理

英文题名：Model Simulation of Solvent Profile in the Preparation of PVDF Membrane and the Mechanism of Macrovoid Formation

作者：杨晓天[1];魏永明[1];许振良[1]

机构：[1]华东理工大学化学工程研究所膜科学与工程研发中心,上海200237

年份：2007

卷号：33

期号：5

起止页码：610

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;EI(收录号：20074710937341);Scopus;北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；

基金：国家973重点基础研究发展计划(2003CB615705)

语种：中文

中文关键词：聚偏氟乙烯;添加剂;浸入沉淀相转化;扩散模型

外文关键词：PVDF; additive; immersion precipitation phase inversion; diffusion model

摘要：采用改进的浸入沉淀相转化法测定了聚偏氟乙烯(PVDF)/添加剂/二甲基乙酰胺(DMAc)铸膜液体系在成膜过程中溶剂的溶出量和溶出速度。实验过程中保持PVDF质量含量15%不变,采用的添加剂包括PEG200(聚乙二醇200)、PEG2000和聚乙烯吡咯烷酮(PVP)。拟合实验数据得到了溶剂在膜中的扩散系数,在此基础上以实测结果为边界条件,利用坐标变换后的费克扩散方程计算了膜内溶剂分布随时间变化的情况。根据计算结果与电镜照片,讨论了不同添加剂形成不同大孔长度的PVDF膜结构的现象。结果表明:膜内溶剂的浓度高、保留时间长有利于大孔向底部发展。
Out diffusion behaviors of solvent in PVDF/Additive/DMAc dope solution were investigated using an improved immersion precipitation phase inversion method during membrane preparation. The mass content of PVDF in the dope was fixed as 15%. PEG200, PEG2000 and PVP were used as additives. Diffusion coefficient of solvent in the membrane was obtained from the experiment results by a curve fitting method. Using measured data as boundary condition, coordination transferred Fick＇s equation was employed to calculate the solvent profiles in the membranes. Simulation results and SEM photos were combined to explain the phenomenon that different additives corresponded to different macrovoid＇s length. The results show that high solvent concentration and long retain time favor the growth of macrovoid to the bottom of membranes.